Shape control of the tension truss antenna

The tension truss antenna is a deplorable mesh surface antenna featuring a cable network, called a tension truss, that gives a parabolic shape to the reflective mesh. Cables in the tension truss are rigid enough to prevent their elongation due to the tension, and the number of nodes and cables satisfies the statically determinant condition. In this paper, surface sensitivity to magnitude and direction errors of the applied force, which gives the tensile force to the tension truss, is evaluated by Monte Carlo simulation. Results show that the surface deformation of a tension truss antenna is smaller than that of an antenna whose cable network is made of flexible cables. A surface control algorithm is derived using the perturbation method, and numerical simulations and experimental verifications of the algorithm are carried out. Results show that the surface shape of a tension truss antenna can be controlled by changing cable lengths, and local surface deformations can be improved without affecting the shape of the other parts of the surface. It is concluded that the tension truss antenna is a promising candidate for a large space antenna.